1. Field of the Invention
The present invention is directed to a finger-operated spray pump ejaculating liquid contents in a fixed quantity at one-time pumping, and more particularly a spray pump in which a poppet valve and a sliding seal are made as one unit and the structure of the housing is modified for lower defect rate and improved convenience.
2. Description of Related Art
Finger-operated spray pumps have been used to the upper caps of the liquid-containing vessels such as metal cans, glass bottles and plastic bottles, i.e., vessels containing liquids like perfumes, hair-spraying agent, deodorizing agents, neck-spraying agent and the like. Using the spray pumps relieves the troublesome operation of opening and closing the cap of the vessels and difficulty spraying in a fixed quantity. Moreover, liquid contents contained in the vessels are not almost dried and deteriorated by external materials because the contents are continuously kept under the closed state.
The representative example of these finger-operated fixed-quantity spray pump is shown in U.S. Pat. No. 5,277,559. The structure and operation of the spray pump in the above patent will be described with reference to FIGS. 1 and 2.
Referring to FIG. 1, the conventional finger-operated fixed-quantity spray pump comprises an actuator (100), a pump member (200) and a sealing cap (300) in a whole view. A piston (220) with an influx passage therein is engaged to the lower portion of the actuator (100). The actuator (100) has an ejecting nozzle (not shown) led to the influx passage of the piston (220).
The pump member (200) includes a housing (210) forming the external appearance, a piston (220) being engaged to the actuator (100) and moving upward/downward in the housing (210), a poppet valve (230) being installed in the piston (220), a sliding seal (240) being close-contacted to the inner surface of the housing (210) and being installed in the lower portion of the poppet valve (230), a spring (250) being installed between sliding seal (240) and the lower portion of the housing (210).
The sliding seal (240) is disposed on the lower portion of the housing (210) and poppet valve (230) at their axis direction, and assembled to move together with poppet valve (230).
A tube (not shown) is extended to the inner bottom of a vessel containing liquid contents and engaged to the lower end of the pump (200).
The spring (250) is disposed in the pump member (200), and its lower end is mounted in the lower space of the housing (210) and its upper end is engaged to a downward extension pin of the poppet valve (230).
The sealing cap (300) is combined to the corresponding portions of the housing (210) and piston (220), with a liner (310) being installed to prevent the leakage of the liquid contents.
The operation way of the finger-operated fixed-quantity spray pump having such structure will be described with reference to FIGS. 1 and 2.
When the actuator (100) is pressurized, the pressure is transferred to the poppet valve (230) and sliding seal (240) via the piston (220). At this time, a downward slope (231) at the lower portion of the poppet valve (230) becomes contacted to an inner lip (241) of the sliding seal (240), and an outer downward slope (242) of the sliding seal (240) becomes contacted to an upward slope (213) of a housing bead (212). As the poppet valve (230) goes down continuously, the inner lip (241) of the sliding seal (240) slides on an outer surface (2310) beyond the downward slope (230) of the poppet valve (230). Since the outer surface (2310) of the poppet valve (230) and the inner lip (241) of the sliding seal (240) are kept at the closed-contact state, an upper space (A) of the housing (210) is closed against a lower space (B). Therefore, the continuous going-down pressurizes the liquid contents being in upper space (A). When the pressure of the liquid contents is sufficient to overcome the spring (250) force, the closed-contact portion of the piston (220) and poppet valve (230) becomes opened, and the liquid contents goes up through the opened portion.
Upon release of any actuating force on the actuator (100), the piston (220) and poppet valve (230) go up together with the sliding seal (240). At this time, the opened space between the piston (220) and poppet valve (230) becomes closed again by the spring (250) force, the closed-contact between the outer downward slope (242) of the sliding seal (240) and the upward slope (213) of the housing bead (212) is disengaged, thereby allowing the upper space (A) and lower space (B) of the housing (210) to be connected through an influx passage (243) to make the flow of the liquid contents possible. The sliding seal (240) goes up only until the outer upper slop (244) of the sliding seal (240) becomes contacted to the downward slope (214) of the housing bead (212). The outer surface (2310) of the poppet valve (230) goes up continuously, with keeping the closed-contact state to the inner bead (214) of the sliding seal (240), even after the contact of the above two units (244, 214), and finally the closed-contact is disengaged upon arrival at the downward slope (2310). Accordingly, the liquid contents in the housing lower space (B) flow into the housing upper space (A) so as to recover the pressure.
As described above, in the figure-operated fixed-quantity spray pump of such structure and operation, the poppet valve (230) and sliding seal (240), and the inner bead (212) conducting the opening/closing procedure by its mutuality with the above two units (230, 240) are very important. However, in an injection molding out of plastic, it is difficult to make the inner bead (212) in the identical form as designed because it is deeply located on the inner surface of the housing (210), particularly, in the case of very small size products like the figure-operated fixed-quantity spray pump. In other words, even the small error of the molded product may make the operation of the spray pump impossible. For example, if the protruding high of the inner bead (212) is a little lower than that in the design, the outer downward slope (241) of the sliding seal (240) cannot keep the closed-contact state to the upper slope (213) of the inner bead (212) and resultantly goes beyond the inner bead (212), which make the pumping impossible as described above. Furthermore, it is very difficult to check such defect of the inner bead (212).
Meanwhile, the ejection amount of the spray pump at one-time pumping depends upon the volume of a precompression part (corresponding to “A”), and in order to increase the ejection amount of one-time pumping, the volume of A should be increased, which requires extending the length or diameter of the housing.
However, the demand on the small-size pump is actually very high for the elegance of the appearance. The pump structure of the above U.S. patent has the inevitably small volume of the precompression part (A) because many units are necessary for operation.
Moreover, the sliding seal (240) is mainly made out of polyethylene resin for the flexibility of the unit; however, the polyethylene resin has a low dimensional-stability at the higher temperature of the molding procedure due to its low melting point.
Therefore, the structure of the spray pump capable of solving said problems is strongly required.